ឥទ្ធីពលនៃកាលបរិច្ចេទដាំដុះលើពេលវេលាចេញផ្ការបស់ពួូលស្រូវធ្ងន់មួយចំនួន (effect of seeding date on heading time in some late duration rice varieties) 430 HEANG, DANY. AGR HEA 2000 B022 Or.1 Phnom Penh RUA 2000 2000 Text 65p. eng